MIKROE-1205 mikroElektronika, MIKROE-1205 Datasheet - Page 33

• Manufacturer Part Number: MIKROE-1205
• Description: Development Boards & Kits - PIC / DSPIC EasyPIC FUSION v7 dsPIC33 PIC24 PIC32
• Manufacturer: mikroElektronika

Specifications of MIKROE-1205

• Rohs: yes
• Product: Development Boards
• Tool Is For Evaluation Of: PIC24x, dsPIC33x, PIC32MX4xx, PIC32MX7xx
• Interface Type: CAN, I2C, SPI
• Operating Supply Voltage: 7 V to 23 V
• Data Bus Width: 16 bit, 32 bit
• Dimensions: 266 mm x 220 mm
• For Use With: PIC24x, dsPIC33x, PIC32MX4xx, PIC32MX7xx

BUZZER
BUZZER
BUZZER
Piezo Buzzer
Piezoelectricity is the charge which accumulates in
certain solid materials in response to mechanical pressure,
but also providing the charge to the piezo electric material
causes it to physically deform. One of the most widely
used applications of piezoelectricity is the production of
sound generators, called piezo buzzers. Piezo buzzer is
an electric component that comes in different shapes and
sizes, which can be used to create sound waves when
provided with analog electrical signal. EasyPIC Fusion
comes with piezo buzzer which can be connected to RD3
microcontroller pin. Connection is established using SW14.8
DIP switch. Buzzer is driven by transistor Q1 (Figure 19-1).
Microcontrollers can create sound by generating a PWM
(Pulse Width Modulated) signal – a square wave signal,
which is nothing more than a sequence of logic zeros and
Freq = 3kHz, Duty Cycle = 50%
Freq = 3kHz, Duty Cycle = 80%
Freq = 3kHz, Duty Cycle = 20%
R35
10K
R35
10K
R35
10K
Figure 19-1: Piezo
buzzer connected to RD3
microcontroller pin
R28
1K
R28
1K
R28
1K
DATA BUS
VCC-5V
VCC-5V
VCC-5V
Q1
BC846
Q1
BC846
Q1
BC846
PZ1
BUZZER
PZ1
BUZZER
PZ1
BUZZER
v7
PERSPECTIVE
PERSPECTIVE
PERSPECTIVE
VIEW
VIEW
VIEW
VIEW
VIEW
VIEW
TOP
TOP
TOP
Freq = 3kHz,
Volume = 50%
Freq = 3kHz,
Volume = 80%
Freq = 3kHz,
Volume = 20%
RD3
™
v7
SW14
ones. Frequency of the square signal determines
the pitch of the generated sound, and duty cycle of
the signal can be used to increase or decrease the
volume in the range from 0% to 100% of the duty
cycle. You can generate PWM signal using hardware
capture-compare module, which is usually available in
most microcontrollers, or by writing a custom software
which emulates the desired signal waveform.
Supported sound frequencies
Piezo buzzer’s resonant frequency (where you can expect
it's best performance) is 3.8kHz, but you can also use it to
create sound in the range between 2kHz and 4kHz.
How to make it sing?
Buzzer starts "singing" when you provide
PWM signal from the microcontroller
to the buzzer driver. The pitch of the
sound is determined by the frequency,
and amplitude is determined by the
duty cycle of the PWM signal.
BUZZER
R35
10K
R28
1K
VCC-5V
Q1
BC846
PZ1
BUZZER
PERSPECTIVE
VIEW
VIEW
TOP
Enabling Piezo Buzzer
In order to use the on-board Piezo Buzzer in
your application, you first have to connect the
transistor driver of piezo buzzer to the appropriate
microcontroller pin. This is done using SW14.8 DIP
switch which connects it to RD3 pin.
Figure 19-2:
push
SW14.8 to
ON position
to connect
Piezo buzzer
to RD3
page 33